Respuesta :

gmany
The formula of the altitude of an equilateral triangle with side x:
[tex]h=\dfrac{x\sqrt3}{2}[/tex]
We have:
[tex]h=6\sqrt3[/tex]
Substitute:
[tex]\dfrac{x\sqrt3}{2}=6\sqrt3\ \ \ |\cdot2\\\\x\sqrt3=12\sqrt3\ \ \ |:\sqrt3\\\\x=12[/tex]

good job